In this paper, the evolution of natural passivation and chloride-induced corrosion, pitting corrosion resistance and corrosion products composition of two Cr-modified reinforcing steels and the low-carbon (LC) reinforcing steel in saturated Ca(OH)₂ solution with chlorides were evaluated by a combined electrochemical measurements (E_corr, LPR, EIS, CV and CPP) and surface analysis techniques (XPS, Raman, FT-IR, and SEM/EDS). The passive films enriched with Cr oxides/hydroxides were formed for Cr-modified steels, resulting in higher passivation capability and corrosion resistance than those of LC steel at natural passivation stage and chloride-induced corrosion stage, respectively. Also, it was confirmed that after chloride exposure, β-FeOOH was widely identified on the outer surface of LC steel, while γ-FeOOH was mainly pronounced for Cr-modified steels. Moreover, compared with LC steel, higher pitting corrosion resistance was evident for Cr-modified steels with various chloride concentrations. Finally, the mechanisms of natural passivation and chloride-induced pitting corrosion for steels in saturated Ca(OH)₂ solution were proposed.

本文研究了在饱和氯化钙（OH）₂溶液中两种铬改性增强钢和低碳（LC）增强钢的自然钝化和氯化物诱导的腐蚀，耐点蚀性和腐蚀产物组成的变化。通过组合电化学测量进行评估（E _corr，LPR，EIS，CV和CPP）和表面分析技术（XPS，拉曼，FT-IR和SEM / EDS）。在Cr改性钢上形成了富含Cr氧化物/氢氧化物的钝化膜，与LC钢在自然钝化阶段和氯化物诱导的腐蚀阶段相比，钝化膜的钝化能力和耐腐蚀性分别更高。此外，已经证实，在暴露于氯化物之后，在LC钢的外表面上广泛地发现了β-FeOOH，而对于Cr改性钢，主要表现出了γ-FeOOH。而且，与LC钢相比，具有各种氯化物浓度的Cr改性钢具有更高的抗点蚀性能。最后，提出了饱和Ca（OH）₂溶液中钢的自然钝化和氯化物引起的点蚀的机理。